Why is My Engine Knocking?

Engine knock is one of the most dreaded sounds to hear from your vehicle. The smooth operation of your motor becomes violent and unnerving. This noise is almost impossible to ignore, and that’s good considering that it often means there’s a critical issue in your engine. 

There are a few reasons that your engine could develop knock, and many of them stem from l issues within the motor. You should avoid driving the vehicle as soon as you encounter any knock, as continuing to run it could lead to engine failure.

Why is My Engine Knocking?

Low Octane Fuel

All gasoline is listed by its octane rating. Octane rating is a fuel’s resistance to compression in a cylinder without detonating. 

The higher the octane level of a fuel is, the higher the resistance to detonation is. Certain engines need higher octane fuels, particularly high-performance, and turbo/supercharged engines.. Running low-octane fuel in the wrong vehicle can lead to accidental detonations, knocking, and pinging. 

Using the proper octane-level fuel for your vehicle is essential to avoiding knock and keeping your engine healthy. 

Faulty Spark Plugs

Spark plugs are responsible for igniting the air-fuel mixture at the proper time, pushing the piston down and rotating the crankshaft.. 

Over time, spark plugs can begin to wear out and lose their effectiveness. This can cause mistimed sparks and accidental combustion.

Using the proper type of spark plug and ensuring to replace them at regular intervals (it varies by vehicle) is one of the best ways of maintaining the smooth operation of your engine. 

Bad Knock Sensor

Modern vehicles have sensors that can detect knocking and tell the ECU (engine control unit) to adjust for the issues. When this sensor wears out, the ECU will be unable to adjust the ignition timing and correct the knocking. 

Low Oil

Oil is your engine’s lubrication, which keeps all of its moving parts running smoothly. Without proper oil levels, your engine will run into problems, fast.

This low oil pressure can be a product of a leak or oil consumption within your engine itself. Without lubrication, your engine may produce a loud ticking or knocking noise. 

Continuing to run your vehicle with low oil pressure can cause catastrophic engine failure. If you run into this issue it’s best to top off your oil ASAP and bring your vehicle in to be inspected by a trusted professional. 

oil draining from car

Rod Knock

Rod knock carries a deep knocking noise and is caused by wear over time. The bearings between the connecting rods and crankshafts keep the movement smooth. As these bearings wear out and eventually fail, the rods are given excess room to move around. As the engine continues to run, the rods produce a loud knocking or banging sound as they move loosely around the crankshaft. 

Rod knock is a serious condition. An engine with rod knock will need to have internal work done to replace the worn bearings, and continuing to drive can cause damage to other components as well. 

It should be noted that there are many conditions that lead to a similar sound to rod knock, and having it inspected and diagnosed will give you the most accurate idea of what the next step should be. 

Engine Diagnostics and Repair in Ann Arbor

If you’re experiencing engine knock or any other worrisome engine noises, the experts at Orion Automotive Services will inspect, diagnose, and repair your vehicle with the highest level of quality possible. 

Call or schedule online with us today! Our team is excited to take care of you and your vehicle.

Book with our certified technicians today!


Book with our certified technicians today!